Process for the manufacture



Reissued Feb. 7, 1939 UNITED STATES PATENTIOFFICE 20,997 I ALCOHOLREPELLENT COMPOSITIONS AND PROCESS FOR THE THEREOF MANUFACTURE Emile c.De Stubner, Charleston, w. Va.

plication for reissue No. 164,335

September 17, 1937','Seria;l

"12 Claims. (01. ice-37$ This invention has as one of its objects .theimpartation of alcohol-resistant qualities to compositions such asmolding compounds, plastics, insulating materials, lacquer, paint,varnish, enamels, etc. As the group of alcohols includes many members ofthis family of chemical compounds, I use the term herein as primarilyrestricted to methyl alcohol, ethyl alcohol and propyl alcohols, whichare met with in the market as wood alcohol, denatured alcohol, and asconstituents of many cleaning fluids,. anti-freeze compounds, polishes,etc.

It is also an object of the invention to provide a preparative treatmentfor composition constituents such as plasticizers, softeners, pigments,fillers, resins, solvents, diluents, extenders, cellulose derivatives inform of cellulose esters, cellulose ethers as basic materials in themanufacture of smokeless powder, photographic films, celluloid,artificial leather, talking machine records, sound records, coatingcompositions, buttons, etc., to make such constituents alcoholrepellent. Y

Before the above-named materials become suitable constituents for suchcompositions, it is necessary to obtain them in a condition free fromwater and excess moisture. This dehydration is an important step intheir preparation.

In the present invention I now specifically name soluble celluloses suchas nitrocellulose, cellulose acetate, cellulose ethers and celluloseesters generally when containing water. These substances exist primarilyin the form of disper-' sions in an aqueous medium similar to thedisperse systems disclosed and claimed in my said patents. Theprinciples underlying my thereindisclosed processes are equallyapplicable to the preparative treatment of water-wet cellulosederivatives such as water-wet nitrocellulose or others. 7

Since the products of this invention are mostly of pasty or plasticconsistency, I find that a kneading machine ,for operation under vacuumis the most suitable apparatus. This machine consists essentially of arectangular trough curved at the bottom to form two halfcylinders,'carrying two blades and a perforated pipe on a saddle whichdivides the two half cylinders. The trough is provided with a jacket asis the cover to prevent condensation of vapors on its under side. In thecover are two plate glass observation windows, and a manifold withswing-- ing joints for connection to condenser, receiver and vacuumline. The trough is fitted with a pyramid, counter-balanced cover,carrying a suitable gasket to afiord an air-tight connection with thetrough. The mixing blades are hollow and heatable and may be perforatedto permit agitation both mechanical as well as by gases blown throughperforation. The mixing blades are so designed and located that theysweep the entire area of the half cylinders on each revolution andrevolving toward each other at un- Through one end of the trough isinserted a termometer-wellso that the stem is fully submerged in themass being mixed. In the cover are .openings for vacuum cocks, gauge andther- ,mometer to measure theitemperature of the vapors. When used forthe dehydration processes of water-wet nitrocellulose disclosed herein,such apparatus permits replacement or evaporation 01' the aqueous mediumin the presence of 9, replacing agent. By this means the nitrocelluloseis maintained in a wetted condition at all times and finally remains inthe apparatus wet-- ted with the selected replacingagent and freed ofsubstantially all of the alcohol or water with which the celluloseoriginally was wetted.

By processing water-wet nitrocellulose'in such a machine with atoluene-camphor-solution as the replacing agent, a water-freenitrocellulose plastic will result; By selecting the proper type ofnitrocellulose and regulating the amount.of

camphor to the desired quantity required for photographic film bases,this plastic composition will furnish not only fllmswhich are free fromwater but free from alcohol as well. Again when selecting-a lacquer-typenitrocellulose and using water-free and alcohol-free lacquer base. Inorder to obtain the pigmented lacquer base for colored lacquers one onlyneeds to start with pigmented nitrocellulose which latter is the subjectmatter of my United States Patents No. 2,034,861, No. 1,795,764 and No.1,914,489. I

When compounding lacquers or making films, whether they are clear orcolored with soluble colors or insoluble pigments, it is of utmostimportance that the solid composition constituents, i. e. solublecellulose, resins, plasticizers, pigments, and the volatile andliquidcomponents such as solvents and diluents, are properly balancedand selected. However, when building up the nitrocellulose lacquer fromalcohol-wet nitrocellulose, which at present is the usual commercialform of this important basic material, then the compounder is alreadydeprived of his freedom of selection of such materials because he hasconstantly to take into consideration the alcohol contained in thecommercial nitrocellulose which will average as much as thirty percent.Thus it will be seen that in a gallon of lacquer which contains usuallyeighteen ounces of nitrocellulose on the dry basis, there areincorporated almost eight ounces (one-half pint) of alcohol. As alcoholis a hygroscopic substance, I have discovered that it is the cause ofthe water or moisture content in lacquer or in an ultimate film or thephotographic film base or in smokeless powder. I have also discoveredthat the alcohol is responsible for the transparent blush" or the"gelled film which is of poor adherence to sub-surfaces and of poortensile strength. In addition, alcohol is also subject to oxidation intoaldehydes and acids, and thus is the cause for the progressinginstability of compounds made from alcohol-wet nitrocellulose. This lackof stability has great and very serious consequences when storingexplosives such as smokeless powder or photographic films on anitrocellulose base.

The present invention discloses methods of processing soluble cellulosessuch as nitrocellulose to overcome these defects through the eliminationof alcohol therefrom.

Should it, however, become desirable to process alcohol-wetnitrocellulose for dealcoholization,

then this is accomplished by distillation processes and with distillingapparatus as disclosed and described in my copending application SerialNo. 56,585, filed December 28, 1935. In the present application use ismade of the known physical and chemical laws governing distillation anduses the difference in vapor pressure and of boiling points fordisplacement of one volatile compound and its replacement by another. Iwish it to be understood that this method which is based on the laws ofdistillation, includes an important step as far as economics areconcerned, particularly on account of condensing evaporated alcohol intoits liquid phase and thereby recovering this liquid alcohol, which thuscan be directed back into the manufacturing cycle. In the art ofcompounding compositions with which this invention is chiefly concerned,such distillation steps and the apparatus with which to conduct suchdistillations are novel. Many a useful apparatus which can come intoaction only provided the material to be handled by it is of liquidenough consistency, is excluded because such liquid compositions do notlend themselvesfor application and utilization as end or consumerproducts, whereas distillation processes bring within economic reach thehandling of rather thin liquids which by distilling oil the liquidconstituents, condensing them into their liquid phase, and recoveringthe latter thereby are concentrated to any desired consistency. I shallillustrate my point bythe following: The colloid mill cannot be broughtinto action to process heavy or plastic compounds. Diluting suchcompounds with a volatile solvent prepares them so that they can behandled by the colloid mill. After passing this processing step, i. e.colloid-milling, the treated compound only needs to be distilled to freeit from the auxiliary solvent to obtain'again the original consistencyof the undissolved compound, and yet the original heavy and plasticcompound is benefited by the treatment of passing it through a colloidmill. In daily life one uses the shoe-horn to place the foot comfortablyinto the shoe and when this is accomplished the shoe-horn is taken off.In my above description, I may compare the solvent to the shoehorn, theheavy plastic compound to the foot, the colloid mill to the shoe, andthe distillation process to the step of taking off the shoe-horn.

The foregoing processes may be used to furnish the compounder withsoluble celluloses free from water and also free from alcohol, and ofconsistencies depending upon the character as well as the amount ofreplacing agent left in the mass. Thus, if desired, the fibers ofnitrocellulose may, during processing, be swelled and gelatinized byselecting a toluene plasticizer solution as replacing agent when freeingwater-wet or alcohol-wet nitrocellulose from water or alcohol. Thisdisclosed utilization of the principle of replacement or displacementand removing thereby water or alcohol by means of a replacing agent, isalso the modus operandi when resins, such as gum dammar, ester gum,copal esters like congo glycerine ester, salts of resin acids or theacid itself, synthetic resins like Glypta1s and their mixtures withpigments such as carbon. black, Prussian blue, etc. are to be obtainedfree from water or alcohol or benzol or any other solvent or diluent togive place to the desired substitution or replac-.

ing agent and ingredient.

In the foregoing I have disclosed methods, processes and apparatus whichutilize the laws of physics as means for dehydration anddealcoholization, i. e. by replacement and displacement. I shall nowdisclose processes for dealcoholization by the application of the lawsof chemistry, 1, e. by reacting away"the alcohol. The following examplewill illustrate the process.

Place one hundred pounds of commercial alcohol-wet nitrocellulose intothe above-described apparatus which is preferably made of aluminum.

centrated acetic acid necessary to transform the alcohol contents of thealcohol-wet nitrocellulose into ethyl acetate, the ester. It is optionalto what extent one wishes to modify the alcohol by simply regulating theamount of acid. Ethyl acetate, being an effective solvent fornitrocellulose, of course produces a nitrocellulose solution which inthis case is rather stiff, and therefore the kneading action of theagitators is required. Now add suiiicient toluene or solvent naphtha tofacilitate mixing of the mass of reaction, which now consists ofnitrocellulose, ethyl acetate, toluene, and also the water of reactionbetween the alcohol and acid, and also perhaps some free acid. Theundesired by-products are now distilled off and in the apparatus remainsthe compound of nitrocellulose dissolved in ethyl acetate which, if sodesired, may be extended with toluene.

. My invention, therefore, consists not only in dealcoholizingalcohol-wet nitrocellulose, but also in the making of solutions or dopesfrom the alcohol-wet raw material by means of chemically transforming aWetting agent into a solvent.

Another instance of reacting away alcohol in alcohol containingsubstances is by transforming the alcohol into the correspondingaldehyde or acid by oxidation. A methyl alcohol-wet filler may thusbecome a desirable constituent of a resinous compound during theformation of the resin when this is of the phenol-formaldehydecondensation class. The formaldehyde is in this case furnished byoxidizing the methyl alcohol filler mixture.

Another method of dealcoholization by physical means but differing fromthe above method .inscfar as the alcohol is removed in the liquid phaseby the action of an alcohol-immiscible replacing or displacing agent, isthe following. Such an agent I found in acetyl-ricinolein, the productof acetylation of castor oil. This ester is insoluble in and immisciblewith commercial ethyl alcohol or denatured alcohol and it (the ester) isalso an excellent plasticizer or softener for nitrocellulose. I have nowdiscovered that by kneading together commercial nitrocellulosecontaining about thirty percent of alcohol and this castor oil ester, sothat the mixture becomes a plastic dough-like mass, the alcohol will befound as a puddle on top of this mass from which it can be easily pouredoff.

I claim therefore also as my invention the process which utilizesalcohol-immiscible or insoluble plasticizing agents or softeners todissociate alcohol from alcohol-wet soluble celluloses. and anyseparating process of alcohol in the liquid phase utilizingalcohol-immiscible and alcohol-insoluble displacing or replacing agentsfalls within the scope of my invention.

I shall now disclose by way of examples the.

means by which alcohol-resistant qualities are imparted to compositionswhen alcohol-insoluble or alcohol-immiscible components are incorporatedinto such compositions. It is important to the compounder to have accessto alcohol-free composition constituents for only with such constituentscan alcohol-insoluble and alcohol-immiscible constituents beincorporated. Since alcohol-insoluble and alcohol-immiscible compositionconstituents are precipitated from their solutions by the addition ofalcohol, they will make compositions in which they are incorporated shedalcohol should this come in contact with such compositions. Therefore,lacquer, photographic films, smokeless powder, coating compositions,plastics, etc., when made with alcohol-free and alcohol-insoluble andalcohol-immiscible constituents, become thereby alcohol-proof and theirstability is greatly increased. It is well known to automobile ownersthat in winter, due to occasional spilling of some anti-freeze compound,the hood of a car becomes spotty and often the paint comes off. This iscaused by the alcohol contain-ed in the anti-freeze compound. Would suchautomobile have been painted with a coating composition made inaccordance with my disclosures, the spilling of anti-freeze would haveno effect.

Lacquer manufacturers who wish to incorporate gum dammar intonitrocellulose lacquers know that the commercial resin must undergo apreparative treatment before it can become a lacquer constituent. Thistreatment consists in dissolving the resin or gum in toluene and thenadding denatured alcohol to this fairly concentrated solution. Thisaddition precipitates the alcohol-insoluble part of the resin whichamounts to about twenty-five to thirty percent of the commercial gum andis regarded a total loss. Often this treatment is referred to asdc-waxing, but the precipitate is not a wax, it is the B-resin of thedammar resin which is insoluble in alcocol. (See Thorpe, ChemicalDictionary under Resins.) In contradistinction to present methods, I canutilize the commercial form of gum dammar as it is, because incompositions made in accordance with my disclosures there is no alcoholpresent which could cause the precipitation of this alcohol-insolublefraction contained in gum dammar. The presence of this fraction incompositions is in fact highly desirable because it impartsalcohol-resistance to them. Thus it will'be seen that the advantages ofmy processes are manifested by a product of improved; qualities whichproduct costs less to manufacture than is the cost of productionaccording to present methods. Of course, this insoluble fraction of thegum dammar may be separated as by present methods and it may then bemade a composition consituent in accordance with above disclosures. Theother part of the dammar which contains hydroxyl groups and is of acidcharacter, lends itself to acetylation and the acid character may bemodified either by esterification, e. g. with glycerine, or saltformation, e. g. by treatment with slaked lime.

I have found that when treated with acetic acid or acetic-anhydride orequivalents, the gum dammar, and still'more; so the fraction separatedfrom'the -B --1"es in, exerts 'plasticizing and softening action upon;the fibers of nitrocellulose and therefore becomes useful in themanufacture of celluloid, photographic films, lacquer,

coating compositions, plastics, artificial leather,

etc.

The absence of alcohol in nitrocellulose also permits the incorporationof coumar resins into such alcohol-free nitrocellulose compositionswhereby the property of alcohol-repellence is imparted to suchcompositions.

The above disclosure regarding acetylation or acid treatment of gumdammar also is applicable to other resins such as Congo copal, Zanzibarcopal, Manila copal, or their solutions, and also to other organiccompounds particularly the polyvalent metal salts of hydroxy fatty acidssuch as are derived from castor oil, rape-seed oil, wool-fat, etc.

I have found that such metal salts as for instance acetyl-leadricinoleate, exert a particular protection to a clear film ofnitrocellulose against the destructive action upon it by light rays.Other metals may take the place of lead, such as calcium, zinc,aluminum, etc. One can compare this protective behavior to the action ofmetal foils toward X-rays which are prevented thereby from passagethrough an object.

I claim: s

1. In the preparative treatment of alcohol-wet nitrocellulose forincorporation into substantially alcohol-free compositions, the stepswhich include removing the alcohol by bringing a suitable quantity ofthe alcohol-wet nitrocellulose into intimate contact with a displacingagent for the alcohol and thereafter distilling off the alcohol untilthe nitrocellulose is substantially freed from alcohol and dispersed inthe displacing agent as the dispersion medium.

2. A process for the production of alcohol-retially alcohol-freecompositions, the steps which pellent cellulosic products fromalcohol-wet nitrocellulose, which comprises continuously evaporating thealcohol and replacing the alcohol with alcohol-immiscible replacingagents non-volatile under the conditions obtaining for the evaporationoi the alcohol.

3. A process for the production of alcoholrepellent cellulosic productswhich includes the novel steps of providing a suitable quantity ofalcohol-wet nitrocellulose, and continuously replacing the alcohol witha polyvalent metal salt of an hydroxy fatty acid. I

4. A process for the production of alcoholrepellent cellulosic productswhich includes the novel steps of providing a suitable quantityoialcohol-wet nitrocellulose, and continuously replacing the alcoholwith acetyl lead ricinoleate.

5. A process for the production of alcohol.- resistant cellulosicproducts from alcohol-wet nitrocellulose, which includes the novel stepsof continuously replacing the alcohol therein with toluene whilecontinually evaporating and removing the alcohol.

6. A process for the production of alcoholresistant cellulosic products,which includes the novelstep of replacing an alcoholic dehydrating agentwith a toluene solution of dibutyl phthalate, and thereafter removingthe, alcoholic dehydrating agent from the mass.

7. In the preparative treatment of alcohol-wet soluble cellulose forincorporation into substaninclude removing the alcohol by bringing asuitable quantity of the alcohol-wet soluble cellulose into intimatecontact with a displacing agent for the alcohol and thereafterdistilling off the alcohol until the soluble cellulose is substantiallyfreed from alcohol and dispersed in the displacing agent as thedispersion medium.

8.'A process for the production of alcoholrepellent cellulosicproductsfrom alcohol-wet soluble cellulose, which comprises continuouslyevaporating the alcohol and replacing the alcohol withalcohol-immiscible replacing agents nonvolatile under the conditionsobtaining for the evaporation oi the alcohol. 9. A process for theproduction of alcoholrepellent cellulosic products which includes thenovel steps of providing a suitable quantity of alcohol-wet solublecellulose, and continuously replacing the alcohol with a polyvalentmetal salt of an hydroxy fatty acid.

10. A process for the production of alcoholrepellent cellulosic productswhich includes the novel steps of providing a suitable quantity of al-.-cohol-wet soluble cellulose, and continuously replacing the alcohol witha'oetyl lead ricinoleate.

11. A process for the production of alcoholresistant cellulosic productsfrom alcohol-wet soluble cellulose, which includes the novel steps ofcontinuously replacing the alcohol therein with toluene whilecontinually evaporating and removing the alcohol.

12. A process for the production of alcoholrepellent cellulosiccompositions which comprises replacing the alcohol of an alcohol-wetsoluble cellulose constituent with an alcohol insoluble plasticizer forsaid soluble cellulose and removing the replaced alcohol, whereby thesoluble cellulose constitutent is substantially freed from alcohol,wetted and softened by said plasticizer.

EMILE C. DE STUBNER.

